Preparation of beta-(p-hydroxyphenyl)-isopropylmethylamine



Patented Feb. l, 1939 r UNITED STATES PATENT OFFICE PREPARATION OF B-(P-HYDROXYPHENYL) ISOPROPYLIWETHYLAMINE Gustav Hildebrandt, Mannheim,Germany, assignor to E. Bilhuber Inc., Jersey City, N. J.

No Drawing. Application May 24, 1937, Serial No. 144,547. In Germany May26, 1936 4 Claims. (01. 260-574) The present invention relates to animproved. rosive action on almost all technical materials process forthe preparation of c-(p-hydroxyconstitutes an undesirable reactioncomponent.

phenyl) isopropylrnethylamine.

It has already been proposed toprepare [3-(p- Example 5methoxyphenyl)-isopropylmethylamine by treat 30 gms. ofp-hydroxybenzylmethyl ketone, 3'70 5 ing p-methoxybenzylmethylketonewith reagents cos. of methyl alcohol containing 7.7 gms. of which yieldformic acid and methylamin h ammonia and 50 grns. of nickel catalyst areformyl compound of p-(p-methoxyphenyh-isostirred for 2 to 3 hours at 80C. and 20 atmospropylmethylamine is produced and is sa onificd Dheres hen in a rr n u o lavewith dilute mineral acids. According to anotherAfter separating f m the ys nd wash 10 proposal fi-(p-hydroxyphenyl)-isopropylmeth 1 with alcohol, the solution is acidified with hydroaminem b bt i d from fl-(p-methoxychloric acid and evaporated to dryness, theresiphenyl) -isopropylmethylamine by eliminating the due is dissolved ina small quantity of water and methoxy group with strong acids. theresulting solution is precipitated with potas- The applicant has carriedout this known proc slum carbonate solution. The precipitate is 15 essand, ascertained th t by boiling p-methoxyseparated by suctionalfiltration and washed with benzylmethyl ketone with sodium formate and aSmall q y O W methylamine hydrochloride in the presence of Yield: 30.8gms of base=97% of theory. formic acid and saponifying the resultingformyl fiy yp y p p y i e is compound with dilute mineral acids p-(ptobtained by methylating the base with formalde- 20 oxyphenyl)-isopropylmethylamine can at best be yd d hydrogen or With benzaldehydeobtained in a yield of 40%. If methylamine methyl eformate is usedinstead of methylamine hydro- W at I laim is chloride and sodium formatethe yield of 1. A process for t e preparation o pmethoxyphenyl)isopropylmethylamine is indroxyp yl)- p p Which 0011- 25 creased to 53%.By eliminating the methoxy Sists in ensing p-hydroxybenzylm hyl kegroupfrom the resulting fl-(p-methoxyphenyutone with ammonia, reducing thecondensation isopropylmethylamine by heating the latter with product t te t o e atom to form the correstrong acids the ,d-(p-hydroxyphe l) aiSponding saturated amine and methylating the pylmethylamine can beobtained in yields from resulting b s a th n n om. 30 36% up to 48%. 2.A process according to claim 1, wherein the According t thi in e ti it hb found condensation with ammonia and the reduction of that,B-(p-hydroxyphenyl) -isopropylmethylamin the condensation product areeffected simultacan be prepared in a substantially more simple 3- mannerand in considerably better yields by A process according to Claim w e h35 starting from p-hydroxybenzylmethyl ketone, 0ndensation of the ketonewith ammonia and condensing this with ammonia, thereafter or sih r du tn of t condensation p u t a multaneously reducing the product ofcondensat d c v ytion and finally methylating the resulting base AP1700658 for the Preparation of B- D- 40 at the nitrogen atom in amanner known per e. droxyp enyl) -is0propy1methy1amine, which con- 40The e- (p-hydroxylphenyl) -isopropylmethyls s in con n p-h y m hyl kamine can in this way be prepared in yields of tone With ammonia,hydrogenatine the o d nmore than 90%, whereas according to the knownsation product at the nitrogen atom to form the processes the bestyields obtainable are 48%. corresponding Saturated amine and methylatingThe process of this invention also enables formic t e resulting base atthe nitro en atom.

acid to be dispensed with, which owing to its cor- GUSTAV HII- EB DT-

